A/N: First chapter of my first story. I should introduce myself, eh?

Well, the name's Asymmetric, Tric for short. This is going to be a For Want of A Nail story where, instead of landing in Hollow Bastion, Riku ends up stuck in the Realm of Darkness. It's probably going to be chaptered. So far I have no beta, but that may change.

Reviews – including, you know, actual reviews – would be appreciated.

Oh, and, naturally, I don't own Kingdom Hearts or any of its characters.

Riku's first thought upon waking was the raft, and that was what alerted him to the nature of the storm outside. It was unlike any other he had seen: dark, oppressively dark, as if there was a hole there where something should be, inky, as if there was a substance that sucked out the light. And it was moving, and it was positioned right over their island. Their island -

He almost went outside too quickly to see Kairi, who was running with him, in the same direction. Her eyes brightened, but she was obviously worried. "We need to get to the island!" she said. "The raft is still there!" And it might be destroyed, she didn't say.

She stopped at the main docks, and then said, quietly: "Maybe we can salvage it. You know. Pick up the pieces. Try again some other time."

But Riku was sure that it could be saved. He said so. "We just have to dig it out. Maybe take it to the secret place."

They nodded and grabbed boats. They couldn't talk at first because of the effort of rowing in the storm – the waves were wilder than either had ever seen. And they were – alive, somehow. Riku dipped his hand in and it came out covered with some inky black substance.

But that only made him afraid, and then angry at his own fear, and he pressed onward as Kairi followed a ways behind.

"Do you see that?" Kairi said. "Over by the paopu tree, there –"

Riku did. There was some sort of vortex. It was like a tornado. Except ...

"I'm going to check it out."

"Riku, you could die! We're only worried about the raft! Right?" But the last word was smaller.

"I'll be fine, Kairi, trust me." But she was still unsure, and he would have seen it on her face if she wasn't behind him.

Soon enough they docked, and then parted. Kairi was to head over to the secret place, to prepare a path for the raft. But she looked back at him. "Riku!"

And then he turned around, and smiled. The smile was so different from Sora's. Where Sora's was bright, and cheerful, and happy, Riku's was confident and determined and focused. Sincere.

He'll be fine. Kairi thought.

As she turned around, Riku stepped towards the vortex, and when he crossed the land bridge, the darkness spoke to him.

A princess is stuck in a gated garden, and she leans next to a fountain and puts her feet into the water, while stroking a giant cat. Her vizier secretly (nonchalantly, hungrily) watches her at the same time-

A town square with a guillotine houses not-spirits that move as if they were caught in the wind, while a skeleton in a pinstripe suit corrals them towards a graveyard-

A man in a glowing blue suit is caught in an endless battle for survival against a man in a red suit, and he cannot let the other get the upper hand because he knows the battle can be stopped at any time -

A blond boy looks down at a girl, who has a red hole through her chest. He looks up, and there is a winged man, and the boy's eyes are filled with hate -

And then the darkness took the world-visions away, and replaced them with a feeling of possibilities, worlds, vast knowledge.

The door has opened.

Riku walked forward, but he was afraid, and to his horror, the vortex was feeding on his fear, consuming him.

"I'm not afraid of the darkness!" he said to himself. He said it again louder.

And then his trance stopped. And the pull, towards the vortex, ended. Riku, coldly, clearly, realized that he was about to step in, past something he instinctively knew to be an event horizon, a place-of-no-return. This power was dangerous (yes, said a voice that grew smaller and smaller, waiting for a choice).

"Riku!" Sora was running towards him. Riku turned around.

The door has opened, said the voice. "The door has opened," Riku said, tasting the words in his mouth.

"What?"

"The door has opened, Sora! We can finally go to other worlds now. Once we step through-" Riku turned around, holding his hands to the sky. His voice became slightly manic. "Once we step through, we might not be able to come back. We may never see our parents again. There's no turning back. But this may be our only chance!"

"But - what is that?" said Sora.

Here Riku stopped, as if that wasn't in the script. "Darkness," he said. But he became doubtful, and the darkness took this chance to battle his innate defenses.

Riku doubled over, in pain. At the same time, heartless swarmed around Sora, and as the heartless became bigger, gained helms and twisted smiles, his friend became overwhelmed.

But Riku was fighting his own, internal battle against a mental attack. It was as if the darkness could see their weaknesses. Neither could stand alone, not against these impossible odds.

But together? said a voice, intrigued.

And then, suddenly, Riku stood atop a circular stained glass depiction of a woman in a long blue dress. The wall of light surrounding the circle trembled once as the darkness tried to gain a hold, then trembled again. A voice appeared in his mind, and Riku knew that it was the key. The key to open worlds.

We don't have much time, said the voice. Why do you want the power of the keyblade?

I need to protect my friends, thought Riku. But he knew that that wasn't the whole answer. He wanted to use the key to see new worlds. He wanted to explore, he wanted to know, because there couldn't be only Destiny Islands. He'd seen people from other worlds, and besides, Destiny Islands was just too small to be all there was.

The circle quaked again, and Riku was sent off balance.

It would be trivial to protect you, kid, but that comes with risk. Darkness ... you don't want to go that route. And you would. I see it in your heart.

I've always been protecting him, thought Riku.

He doesn't need it, countered the voice. His heart is just as strong as yours. Whether it is more so remains to be seen, and I don't know where the hell he got it from, but there is potential to use the Keyblade. And his would not be influenced by darkness as yours was.

I- said Riku. My world was ruined by darkness, he yelled, and Sora is out there, and he might die, and I can't just leave him. I need them both. We were going to explore together, you stupid key. Don't take that away from us.

I'm not your key, said the voice, sadly. I guess you really don't remember. Let me show you.

What - Riku said, startled. Then who -

And then the darkness broke in.

.

.

"Are you awake?"

Riku woke up with a start, and gasped. Then he saw a figure, a woman, and she was looking down at him.

His eyes narrowed. "Who are you?"

She laughed. "Don't you remember?" She bent down, so he could see her more closely. She had blue hair and eyes.

"I'm sorry. I don't think I ever introduced myself. My name is Aqua."